Demographic analysis based on the growth parameter of sharks

Demographic analysis can be a useful tool for effectively estimating and managing shark stocks. However, it requires parameters of instantaneous rate of natural mortality (M), mean age at first maturity (tα), longality (tλ) and natality (mt), which are hard to obtain. In this article, On the basis of some ameliorated empirical formulae, we estimated M, tα and tλ using von Beterlanffy growth parameter first. Based on these parameter, we performed a demographic analysis for 18 shark populations, which yield intrinsic rate of increase (r0) ranging from 0.055 to 0.355 year−1, reproduction rate per generation (R0) ranging from 1.411 to 21.236, generation time (G) ranging from 3.094 to 41.696 years, time of population doubling (tx2) ranging from 1.953 to 11.748 years. The r0 and tx2 were affected by maximum age and natality.